Flashcards in TEST 1 Deck (16):
The scandal of proposition logic
• Propositional logic turns out, as being a formal logical system, to be unable to adequately describe our free autonomous human reasoning
• All modern formal logical systems are partially based on propositional logic. The same therefore holds for all these other formal systems
• We derive all this from our free original autonomous thinking, through which we rise above any formalism. Our minds surpass any system.
• The authority may never lie with a formal system, but must rest with the human mind as creator of all formalisms. The absolutisation of a formal system is thus a form of idolatry with regards to our autonomous and free minds.
The Pragmatic Theory of Truth
• A proposition is true iff believing it is useful in the long run and on the whole course. Truth is synonymous with practical success
• Pragmatic theory is form of cognitive relativism. What works for you might not work for me.
• Pragmatic theory violates our intuïtions. Delusions might come out true if believing them results in practical success
• Misrelationship between true belief and mind-independent facts (= the way things are independent of our beliefs)
– Pragmatists (and coherentists) might say objective facts do not exist
Pragmatists seem to conflate truth with justification. But there is a difference between a belief being true and being justified
– We may be justified in believing propositions that are not true
– We may not be justified in believing propositions that are true
• Pragmatism seems ultimately to depend on an objective notion of truth. For to adequately say that some belief works, it must be the case that the proposition ‘It works’ corresponds to facts
• So it seems better to reserve the term ‘truth’ for propositions that communicate objective facts of reality (correspondence)
Three different types of knowledge
• Knowledge by Acquaintance
– Having direct experiental access to either an object or a perception
• Objectual knowledge by Acquaintance (I know that tree across the street)
• Perceptual knowledge by Acquaintance (I know my perception of a tree)
• Competence Knowledge (‘skill’ knowledge, ‘tacit’ knowledge)
– Knowing how
• Unconscious competence knowledge (I know how to ride a bicycle)
• Conscious competence knowledge (I know how to program a computer)
• Propositional Knowledge (descriptive knowledge)
– Knowing that some proposition is true (I know that Paris is the capital of
France; I know that snow is white, I know that 2 is a prime number)
A proposition is the meaning of an assertoric sentence. An assertoric
sentence is a sentence that purports to assert a truth (e.g., “It rains”)
FROM ARGUMENTATIONS TO ARGUMENT STRUCTURES
• The validity of an argumentation is determined by its structure rather than by what it means.
• To determine whether an argumentation is valid, we must determine its argument structure.
• If the structure is (in)valid, the original argumentation will be (in)valid.
• In short, the task of logic theory is to to discover all possible variants of argument structure.
In "Dissolving the Scandal of Propositional Logic?" two attempts to resolve the scandal are discussed. Describe one of them. Does this attempt succeed?
FIRST ONE: pointing out that this should come as no surprise since material implication A -> B is defined as false IFF A is true and B is false.
- Rutten claims that material implication was introduced into propositional logic in order to capture the notion of implication/logical consequence in natural language, and not just to express some connection of dependence between two statements.
SECOND ONE: reformulating the statement as 'IF A ^ B -> C is provable, THEN A -> C is provable. (FALSE)
- However, Rutten contends that this formalization is too strong and therefore sdoes not succeed in dissolving the scandal.
- Too strong because becomes an instance of that formalizations, and that is not what someone who asserts A ^ B -> intends to say.
- Neither attempt succeeds according to Rutten.
How do we obtain knowledge? According to Plato
• Plato was the first to put forward a full rationalist theory
– The particular objects of sense perception are subject to becoming, change and decay and thus cannot be proper objects for knowledge
– Knowledge goes beyond the changing particular (the world of becoming) and grasps universal ideas or forms. These forms exist in a transcendent, perfect, eternal, unchangeable realm of ideas (the world of being)
– We know forms since we have innate ideas. Knowledge is recollecting what we have learned when our soul was present in the world of being.
– Plato provides the example of teaching geometry by bringing up knowledge from within, by recalling the eternal mathematical forms
John Locke’s representationalism
• All our knowledge derives ultimately from sense experience
• The mind is initially a white sheet (tabula rasa) without any ideas.
• Locke embraces a causal theory of perception
– Objects in the External World come physically into contact with our sense organs
– Our physical sense organs send physical signals to our physical brains
– Our brain transforms these physical signals into non-physical events
– These non-physical events are perceived as mental ideas in our mind
• We aren’t directly aware of the object, only of representation of the object (idea)
• Locke distinguishes two main types of qualities
• Locke distinguishes two main types of qualities
– Primary qualities are inseparable from the external objects (e.g., solidity, extension, figure, mobility, number). Our ideas of them truly represent the objects
– Secondary qualities are not in the thing, but only ideas in our minds (e.g., colour, taste, sound)
• All there is to objects are their primary qualities.
– By virtue of its primary qualities an object has the power to initiate secondary qualities
– By virtue of its primary qualities an object has dispositional qualities (actually a third type of quality!) such as flammability, fragility and solubility
Locke’s representationalism might lead to skepticism
If Locke is right we never have direct access to the objects themselves, only to representations (ideas) in
our mind. So, how do we know if these ideas faithfully represent the external world? In fact, is there an external world at all?
Berkeley’s attack on Locke’s representationalism
• According to Berkely Locke’s primary/secondary qualities distinction is weak. The primary qualities are no more in the objects than the secondary ones. Both types of qualities are mind-dependent. Berkeley raised four objections to Locke.
1. “If heat and cold are affections only in the mind, because the same body which appears cold to one hand seems warm to another, why may we then not as well argue that figure is only in the mind, because the same body which appears circular (or small) to one seems elliptical (or large) to another”
2. Perceptions cannot resemble physical objects. “An idea can be like nothing but an idea” (logical problem)
3. Locke needs the notion of substance (the bearer of primary qualities). But what is the difference between “something I know not what” (Locke’s notion of substance) and nothing at all?
4. Locke’s causal theory of perception is an explanatory failure. How could physical events
produce radically different mental events (e.g., light waves the sensation of redness)?
Berkeley’s own solution to how we know the external world.
• Berkeley denied the existence of matter. Only minds and mental events exist (idealism, classical phenomenalism). Physical objects are thus simply mental events
• Intractable problems disappear: What is substance? How can the physical cause the mental (and vice versa)? How can we have knowledge of the external world?
• All qualities (shape, colour, etc.) are secondary. They are real because they are being perceived: esse est percipi
• Hence, a physical object would cease to exist if not perceived. But what then happens to a tree if it is not perceived by us human beings? Does it cease to exist? No, God sees it!
• Locke could not show that God exists necessarily: Lock’s system can be interpreted purely naturalistically. But in Berkeley’s system God is necessary. God is needed to keep our world intact.
• God communicates directly with our finite minds by the mediation of ideas, thus constituting that what we call the external world (the world of trees, cars, etc.).
The anti-metaphysical movement
• By the late 1940s logical positivism or logical empiricism represented the furtherest advance of the anti-metaphysical movement
• Logical positivists launched the verification criterion. Empirical verifiable statements are cognitively meaningful, empirical unverifiable statements
are cognitively meaningless
• The chief architect of logical positivism was Rudolf Carnap. He had a puritanical devotion to empiricism, and offered a radical deflationary view of metaphysics
• According to this view all questions of traditional ‘a priori’ metaphysics are pseudo-questions. They lack cognitive content (and can’t therefore be objects
of thought or assertion)
• So, by the late 1940s metaphysics was supposed to be on its last legs.
Actually, it was supposed to be dead. One believed to have finished what Kant started
Quine’s method for doing serious Ontology
• On the now dominant Quinean view, metaphysics is about what there is. Do properties exist? Do numbers exist? Do meanings exist? Do tables and chairs
exist? Do temporal parts exist? Mereological sums? Propositions? Etc.
• Quine’s four-stage indispensability method for doing serious ontology
(1) Identify the best scientific theory (physics for Quine)
(2) Identify the canonical logic (first order predicate logic for Quine)
(3) Translate the best theory into the canonical logic (some paraphrasing allowed)
(4) Determine the ontological commitments required to render this translation true
Example: The indispensability of mathematics to empirical science gives us good reason to believe in the existence of mathematical entities. Reference to mathematical entities such as numbers is indispensable to our best scientific theories, and so we ought to be
committed to the existence of these entities (Quine-Putnam indispensability argument)
Describe the theory of knowledge that Meillassoux has coined “correlationism”.
We can only access the correlation between thinking and being, and never being itself. What we call “reality” appears inescapably as the correlate of our language or thought. We therefore have only access to how the world is for us and never to how the world is in or on itself.